| Abstract: | Feedback from supermassive black holes is now thought to be one of the key components of galaxy formation. It is well known that active nuclei are capable of launching powerful winds and jets, but until recently the impact of these phenomena on galactic scales was poorly measured and poorly understood. A major difficulty is that quasar-driven winds are multi-phase phenomena, and different phases require observations using different tracers. It is not yet known which phase dominates the energy and the momentum of quasar-driven winds on galactic scales. I will review observational techniques used in measuring winds from active galactic nuclei and in measuring their impact on galactic scales, summarize exciting recent results and discuss unsolved problems and outstanding issues. I will also briefly discuss ongoing work to discover small-separation dual quasars. |